Bus topology and Star topology
This article will discuss the differences between the bus and star topology in detail. In the beginning, we will learn the meanings of bus and star topology. After that, we will learn some of the differences between these two topologies.
Bus Topology:
In a Bus topology, there is a single communication line or cable shared by all the nodes in the network by drop lines and taps, as shown in the following figure:
In the above figure, the drop line connects the nodes and the mainline, using a tap to add another device to the main cable. When one computer sends a signal up the cable, all the computers on the network receive the information. Still, the message is accepted by only that computer whose address is specified in the message's address field, and the rest of the nodes reject the message.
Star Topology:
In star topology, there is a central controller called a hub. In this topology, each node in the network has a dedicated point-to-point link to this central controller device, also known as a hub. The following figure displays the working of star topology:
There is no direct link between the nodes in the above figure, and all these nodes communicate via a hub only.
Following are the comparisons between the Bus and Star topology
| Sr. No | Basis | Bus Topology | Star Topology |
|---|---|---|---|
| 1 | Connection of nodes | In a bus topology, all the nodes are connected to a single communication line with the help of drop lines and taps. | In star topology, all the nodes are connected to a central controller called a hub with a dedicated point-to-point link. |
| 2 | Expansion of nodes | In a bus topology, expansion is easier. A new node can be easily added using a connector. | In star topology, expansion is very easy. A new node can be easily connected using a central hub. |
| 3 | Chances of data Collison | In a bus topology, the chances of data collisions are very high. | In star topology, the chances of data collisions are very low. |
| 4 | Failure of a node | In a bus topology, the failure of a node does not affect the whole network. | In star topology, the failure of a node affects the whole network. |
| 5 | Fault identification and Isolation | In a bus topology, fault identification and Isolation are difficult. | In star topology, fault identification and Isolation are very easy. |
| 6 | Access Rate | Sharing a single channel results in a slower access rate in a bus topology. | Access rate is very fast as each node has a dedicated point-to-point link in a star topology. |
| 7 | Cabling Cost | In a bus topology, cabling cost is low as only a single cable is required to connect n nodes. | In star topology, cabling cost is high as n-1 cables are required to connect n nodes. |
| 8 | Signal Transmission | In a bus topology, the transmission of the signal is unidirectional | In star topology, the transmission of the signal is not unidirectional. |
| 9 | Network orientation | In a bus topology, network orientation is linear. | In star topology, network orientation is non-linear |
| 10 | Speed of data transfer | In a bus topology, the data transfer rate is slow. | In star topology, the data transfer rate is fast. |
| 11 | Congestion control | In a bus topology, the signal send from source to broadcast, and it travels to all working stations connected to cable, so there are no chances of congestion. | Star topology gives much better performance because signals don't necessarily get transmitted to all the workstations connected to the network. |
| 12 | Security | In a bus topology, any computer that is connected to a network will be able to see all the data transmissions on all the other computers. So there are no chances of security. | In a star topology, security depends on the central device. |
| 13 | Response time | In a bus topology, response time is slow. | In a star topology, response time is good. |
| 14 | Complexity | In a bus topology, easy to connect or remove nodes in a network without affecting any other node in a network. | In a star topology, average complexity because each device connects to central device with only one link only. |
